THE PROPOSED PROGRAM IS TO PERFORM STUDIES LEADING TO THE DEVELOPMENT OF A SURFACE ACOUSTIC WAVE (SAW) TRANSDUCER FOR ON BOARD AIR-DATA SYSTEM. THE OBJECTIVE OF THE PROPOSED PROGRAM IS TO DEVELOP A HIGH PERFORMANCE DIGITAL RATE-OF-DESCENT/ALTIMETER TRANSDUCER WHICH WILL UTILIZE STATE-OF-THE-ART SAW TECHNOLOGY. PRELIMINARY ANALYSIS SHOWS THAT SAW TRANSDUCER HAS: (1) A DYNAMIC RANGE OF 10 TO THE 6TH POWER, THUS GIVING AN ACCURACY OF LESS THAN 0.01 FT. IN 1000 FEET, (2) THE ALTITUDE QUANTIZATION RATE OF 0.5 FT/HZ, AND (3) AN EQUIVALENT SAMPLING RATE OF 60 KHZ (APPROXIMATELY 2/16 BITS/SEC.).